In the related art, a vehicle has a power generator mounted thereon so as to supply power to various electrical loads and to charge a battery. The power generator is driven by an internal combustion engine to generate power. Therefore, when the internal combustion engine is in operation (excluding when fuel is cut off), fuel is consumed also for the power generation.
In contrast, in recent years, improvement in vehicle fuel efficiency has been desired in view of environmental problems. There have been proposed a method of actively generating power when fuel is cut off in the internal combustion engine, such as when the vehicle is decelerating (hereinafter referred to as “power regeneration”), so as to decrease the chance for the internal combustion engine to perform power generation involving fuel consumption (hereinafter referred to as “combustion power generation”), and a method of setting an operating region of the internal combustion engine as a condition for performing the combustion power generation so as to reduce the amount of fuel to be consumed for the power generation (see Patent Literature 1). In the related art, based on a fuel consumption amount map in which an increased amount of power of the internal combustion engine due to power generation is added, power generation is performed in an operating region of the internal combustion engine in which the amount of fuel consumption is small. In this manner, the amount of fuel to be consumed for power generation is reduced.